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Rapid removal of cobalt (II) from aqueous solution using cuttlefish bones; equilibrium, kinetics, and thermodynamic study
Author(s) -
Sandesh K.,
Suresh Kumar R.,
JagadeeshBabu P. E.
Publication year - 2012
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.1639
Subject(s) - adsorption , gibbs free energy , freundlich equation , enthalpy , chemistry , cobalt , endothermic process , langmuir , aqueous solution , cuttlefish , sorbent , thermodynamics , inorganic chemistry , physics , food science
The objective of this study is to assess the adsorption potential of cobalt (II) using cuttlefish bones. The bones were treated with 0.01 N HCl to enhance the heavy metal uptake. The adsorbent was characterized using scanning electron microscope and energy dispersive X‐ray spectrometer. An adsorption study was conducted in a batch system to optimize process variables such as initial concentration of cobalt (II), pH, sorbent loading, particle size, process temperature, and contact time. The optimal pH was found to be 9. The kinetic data followed the pseudosecond‐order kinetic model, and the equilibrium time was found to be 20 min. In the first minute of the adsorption process, 50% of the cobalt (II) was adsorbed by the cuttle bones. Adsorption isotherms were expressed by the Langmuir and Freundlich adsorption models. The Langmuir adsorption model fits the experimental data reasonably well compared with the Freundlich model. The maximum adsorption capacity of this new sorbent was found to be 76.6 mg g −1 at 40 °C. Thermodynamic parameters, including the Gibbs free energy (Δ G o ), enthalpy (Δ H o ), and entropy (Δ S o ), indicated that the adsorption of cobalt (II) by cuttlefish bones was feasible and endothermic at a temperature range of 20–40 °C. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.